Electric switch



Sept. 11,1928.

D. F. JONES ELECTRIC SWITCH Filed June 14, 1926 F Wk Patented Sept. 11, 1928.

PATENT oer-ice.

Don 1. Jones; 01' Baron, WISCONSIN.J

ELECTRIC swrrcn. I

Application flled'J'une 14, 1926; SeIiaIiNm 115,711.

My invention pertains more particularlyto that type of electric switches knownas start 1 and stop push button switches which are used in the control of an electrically actuated 5 device such as an electricmotor.

This type of switch has commonly been used as means whereby" an electricmotor could be started or stopped'from any. one of: a number of points remote from the motor. It

has been customary in this artto provide two separate actuating buttons for the switch"; one to start, and the other to stopzthe motor. I have foundthat this method involves anunnecessary multiplicity of parts, and it is,

therefore, an object of my invention to provide a control switch of this type in whichone button is used to control both thestart and the stop circuits. I I

Another object of my invention is to'provide a control switch of the type described in which the operating button may be locked to hold the switch in a neutral 'or-open position.

A more general object isto provide a new and improved switch which issimple and inexpensive in construction, which is efficient and certain in, operation, an d which has a high factor of safety due to the impossibiht of accidental actuation'of the switch.

Other objects and advantages will become apparent from the following specification showing the; means for'holding the contactsin a neutral or openposition.

, Fig. 6 is a fragmentary sectional view showing a modified formof Mocking member. g y

Fig. 7 is a fragmentary front view ing the modified look of Fig.6.

While I will herein disclo'e the preferred embodiment of lily-invention inconsiderable particularity,for the sake of clearness,;l' recognize that various alternatives will occur to persons skil'led'in this art and Itherefo're do not confine my invention to the presentrdlsshowclosure but aim to cover in theappended claimszall modificationsand equivalents fall ing'within the scope of the invention.

My device comprises a pair of; contact membersmounted', relatively to an operating member and movable thereby so that actuation of the operating member axially in one direction will move one of said contact members to close a circuit, and actuation of said operating memberin the, opposite direction will move the other oi: saidgcontact members tobreak a'circ'uit.

Thefpret'erred form of: my invention, as shown in the drawings, comprises a suitably shaped or'moulded base 10 of-any good ins1ilating material, adapted to be secured in a protecting casingll as by means of. bolts 12.

The switch membersaresecured upon the base, and as shown comprise three substantially Z-shapedterminals lii, 14: and 15, preferably formed of a very good conductor of electricity, such as heavysheet copper. To these terminals the various circuit leads are securedby means of screws or binding posts 16. Each of the three terminals is secured upon the base through one of the arms of the terminal 13 is secured onthe opposite end: of the base*10jso-th at the outer arm 19 of that terminal lies in substantial alinement with the overlying arms on the terminals'14 and415. Mounted upon the arm-19 of the terminal 13, as shown in Figs. 1 and 3, are two contact members which preferably'are in the form of bars 20 and-'21 adapted to coact selectively with the spaced arms 17 and 18 to control the circuit. The contact barsmay be mounted on the arm 19 in any suitable manner which will permit lateral movement t'oiand from thebase 10 but I prefer to mount themlso that a re- 'Z,.thus positioning the other arm in parallel silient means may be readily: incorporated therewith. As shown, a single stud, which may bei'n the form otabolt 22passesthrough the arm 19 of the terminal 13' and also throughone end of each of the contact barsfZO and 2T which, are. positioned on opposite sides .1 of the arm. Encircling the'bolt 22 aretwo helical springs 23 and 24;, one being positioned between the head 25 the boltn2% and the contact bar 21 and the other bearing upon the nut 26 on the bolt 22 and the contact bar 20.

By so mounting the two contact bars on the terminal 19 I have provided a simple and eti'ective contact therebetween, and at the same time have incorporated therein the springs 23 and 2st through the agency of which the contact bars will be caused to return to a normal position as will be hereinafter described.

The free ends of the contact bars are offset in opposite directions to such extent that when they are held in a normal position by the two springs the outer contact bar 20 will engage the terminal arm 17 while the inner contact bar 21 will be spaced away from the terminal arm 13. in this manner, I have provided what may be termed a normally closed circuit through the terminal 13, contact ba 20 and the terminal 14, and a normally open circuit through the terminal 13, the contact bar 21 and the terminal 18, any force acting to change the normal position of these contacts being resisted'hy the springs 23 and 2st. hen the switch is assembled in a control circuit the nori'nally open contacts comprise the starting switch and the normally closed contacts comprise the stopping switch.

The preferred means by which I actuate the contact arms comprises a cylindrical plunger 27 adapted to reciprocate in a hole 28 through the base 10. A pin 29 to one end of which the plunger 27 is rigidly attached, is freely slidable through appropriate openings in the contact bars 20 and 21, and has secured on its outer end an insulated operating handle 30. The length of the pin 29 is such that when the contact bars 20 and 21 are in normal position the lower bar ill will be adjacent the plunger 27 and the upper bar 20 will be adjacent the handle 30.

It will be seen that-by pushing in upon the operating handle 30 the contact bar 20 will be moved away from the terminal arm 17 thereby breaking the normally closed circuit. It the handle 30 is pulled out, the contact bar 20 is not disturbed, and the contact bar 21 is moved by the plunger 2? to es ablish contact with the terminal arm 18.

In order to protect the handle 30, I prefer to provide the case 11 with a cover 31 including a central opening 32 through which the handle 30 projects. The cover is formed with an outstanding peripheral flange 33 which serves as a guard againstinjury or accidental operation of the switch.

I have provided simple and effective means for lockin the switch in a neutral position, that is, a position in which the normally closed circuit is held open and the normally open circuit is held against closing. This means, as shown in Figs. 1, 3 and 5, comprises a pin 34: rigid with the handle 30 and adapted to pass through a slot 35 formed with the central opening 32 in the cover. To lock the switch, the handle 30 is depressed until the pin 34 has passed through the slot 35, and the handle is then rotated to remove the pin out of registration with. the slot 35, so that the pin is held against the inner side of the cover 31 by the spring 23. The contact bars 20 and 21 will then beheld in the position shown in tull lines .in Fig. 3. A modified form of locl; is shown in Figs. 6 and 7. In this form, the locl; comprises a plate 36 pivotally secured at one end, as at 37, to the cover 31, and having a linger-piece 33 struck up from the other end. A pin and arcuate slot connection 39 between the cover and the plate 36 allows only limited pivotal movement to the plate. One side of the plate is cut awayto provide asemicireular recess which isadapted to fit into an annular groove ell) on the handle 30, and in this manner to lock the handle and contact bars 20 and 21 in the position shown in Fig. 6.

It will be seen from the toregoin g description that a switch has been provided which is inherently sate. It will be practically impossible for the switch to he accidentally actuated under any circumstances since it requires a positive and deliberate pull upon the handle 30 in order to operate the switch Moreover the switch is relatively sensitive when it is desired to breal; the circuit therethrough, as it is only necessary to depress the handle a short distance in order to move the contact bar 20 outo't engagement of the terminal arm 17. Theloclring means and the flanged cover are other features which lend increased safety to the switch.

The type of circuit in which my switch is adapted to be installed as a remote control or push button station well known in the art, and it is therefore deemed unnecessary to explain in detail the operation of such a circuit. ,Vhen installed in such a circuit, the normally open circuit formed by the terminals 13 and 15 and the contact bar 21. serves to control the means by which a. motor may be started in the following manner. The handle 30 is pulled outwardly, moving the plunger 27 against the contact bar 21 lo l'orce the bar against the terminal arm 18 as shown in broken lines in Fig. 3, thereby closing the normally open circuit. This energizes an electromagnetic switch, which in closing will close an auxiliary switch, thereby completing a maintaining circuit through the normally closed circuit formed by the terminals 13 and 14: and the contact bar 20. The handle 30 may then be released, and the electromagnetic switch will remain closed. To stop the motor, the electromagnetic switch is deenergized by depressing the handle 30 to force the contact bar 20 away from the terminal arm 17 as shown in full lines Fig. 3, thereby breaking the normally closed circuit.

. I claim as my invention:

1. An electric switch comprising, in com blnation, a base, three circuit tern'nnals Imounted on said base, each of said terminals having a contact surface in spaced relation lron and substantially parallel to said base,

. two of said terminals being mounted on'said 'bination, a base, three circuit terminals mounted on said base, two contact bars mounted on one of said termi als, resilient means cooperating with said contact bars to hold said bars yieldingly in engagement with said terminal, one of said bars bein adapted to'contart with one of the remaining terminals to form a normally closed circuit and the other of said bars being positioned adjacent to but out of contact withv the other remaining terminal to provide a normally open circuit, a single means for actuating said bars against the action of said resilientmeans, and locking means whereby both said normally open circuit and said normally closed circuit may he held open.

3. An electric switch having, in combination, a base, three terminals on said base, a contact bar movably mounted on one of said remaining terminals to provide a normally closed circuit, a second contact bar also movably mounted on. said first mentioned terininaland arranged to be moved into contact with. the thirdtermina], thereby providing a normally open circuit, and a single operating means engaging both of said contact bars for opening said normally closedcircuit and for closing said normally opened circuit.

4. An electric switch having, in combination, a base, three terminals on said base, a contact bar movably mounted on one oi. said terminals and having contact with one ofthe terminals and having contact with one of the con ably mounted on said first mentioned tenninal and arranged; to be moved into contact with the third terminalthereby providing a normally open circuit, means for actuating said bars, and locking means cooperating with said actuating means to hold both oi said normal circuits inv an open position.

5. An electric switch having, in combination, a base, three terminals mounted on said base, two ot said terminals being so formed and arran ed' that a portion of one is positioned in "t from and parallel. to a similar portion. or the other, two contact bars pivotally mounted on the third of terminals, and two springs, one cooperating with each of said contact bars to hold said bars in a nonnal posi ion relative to the two first mentioned terminals. i

6. in electric switch comprising, in combin .n, a circuit terminal, two relatively movable contact bars mounted thereon, two springs, one coo 'ierating with each of said .ict bars to hold said bars in engagement with said teri'ninal in predetermined normal positions, a single operating means for imparting movement to said. contact bars, a circuit terminal adapted to be engaged by one cl said contact bars, and a second circuit terminal. adapted to be engaged by the other of said Contact bars, said last mentioned terminals being arranged so that the portions which are engaged by the contact bars are positioned in parallel spaced relation.

7. An electric switch comprising, in com bination, a base, a plurality of terminals mounted on said base, a pliiirality oli' movable contact members mounted on one of said terminals adapted to selectively engage the others of said terminals, yielding means tend ing to hold one oi aid contact members norinally in engagement with another of said remaining terminals to provide a normally closed circuit, a second contact bar alsomovterminals and iding to hold another of said contact members normally out of engagementwith another 01": said terminals and a single actuating means for said contact members,

said means upon movement in one direction tending to separate said. normally closed parts and upon movement in theother direction tei'iding to bring into engagement said normally separated parts.

, In testi'monv whereof I have hereunto at- 7 fixed my signature.

' DON F. JONES. 

